significantly lower on tests that measured visual and verbal memory, visual analysis and planning, and mental flexibility. Those test results suggest that these players would be slower at learning and remembering new material that they hear or see, Dr. Lezak said. The study results were similar for comparisons of amateur as well as professional athletes.

While several studies of European soccer players raise concerns about the possibility, most studies of American soccer players allay those concerns.

The studies of professional soccer players in the Netherlands also found that soccer players who did more heading or experienced more concussions scored lower on visual and verbal memory tests, visual analysis planning and tasks requiring focused attention and visual scanning. But there were differences between the two groups. Players who were frequent headers displayed decrements in both verbal and visual learning and visuographic tracking speed when compared with those who had been concussed more, although the latter group had decrements in visuospatial organization and fine visual discrimination, she said. The differences between these groups reflect the areas of the brain likely to be affected by concussions versus heading, she suggested.

WHAT IS NEUROPSYCHOLOGY?

Neuropsychology is the study of human behavior as it relates to normal and abnormal functioning of the brain. Clinical neuropsychologists apply scientific knowledge about the relationship between brain function and mental performance to help answer diagnostic questions about medical patients.

Neuropsychological assessment uses behavioral methods such as interviews, observations, paper-pencil and computerized tests, or other specialized procedures to evaluate changes in mental abilities and personality as a result of neurologic disorder. A key component of neuropsychological assessment is the administration of tests of mental abilities such as memory and reasoning. An evaluation may also involve assessment of change in personality, behavioral, and emotional functioning that might reflect neurologic dysfunction or psychological reaction to disease.

People may be referred for neuropsychological assessment after a concussion or other head injury to assess whether certain types of brain functions have been affected. Neuropsychological testing provides a wealth of practical information useful to both the physician and the patient. Test results can help clarify the nature of cognitive difficulties and support the formulation of plans for treatment, rehabilitation, and psychological adjustment.

But some of the experts at the workshop questioned the validity of these findings of adverse effects of heading, and soccer playing in general. Dr. Kirkendall pointed out that the results from studies of European soccer players may not be comparable to those of players in this country, because the Europeans generally use balls that are more highly inflated and thus have more impact when they strike the head. “The alarming numbers we saw from some of the European studies may not translate to the population here,” agreed Dr. Guskiewicz. Dr. Kirkendall added that findings in professional soccer players, who are high-caliber, aggressive athletes may not be applicable to middle or high school soccer players.

To date there has been no published study that has provided direct evidence that the practice of heading a soccer ball causes long-term deficits in mental functions. While several studies of European soccer players raise concerns about the possibility, most studies of American soccer players allay those concerns. However, few of those studies were designed to directly study the effects of heading the ball, because they were cross-sectional studies, based on players’ condition at only one point in time with no information about their condition before they became elite soccer players. Dr. Kirkendall described one prospective study in which the consequences of heading could be directly assessed by comparing players before and after heading the ball. That study, by Dr. Margot Putukian, showed no differences on neuropsychological tests before and after heading, although that was a short-term study not designed to detect long-term effects. In 2002, Dr. Kirkendall and his colleagues will launch a 5-year longitudinal study of soccer players on the United States National Youth teams. That study should be able to settle the question as to whether heading the ball is followed by brain injury, at least among players at this level. (At ages 16-21, these are already elite soccer players competing at a much higher level than children who play on recreational teams.)

Summing up the human findings presented, Dr. Echemendia said, “The data show that, all



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